Amplifier



FIG. 1 is a perspective of an amplifier showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a left side elevational view thereof;

FIG. 4 is a front elevational view thereof;

FIG. 5 is a right side elevational view thereof;

FIG. 6 is a rear elevational thereof; and,

FIG. 7 is a bottom plan view thereof.

The ornamental design for an amplifier, as shown and described.